The unique structural characteristics exhibited by a novel mitochondrial genome derived from the mosquito-parasitic nematode Romanomermis culicivorax will be exploited to develop an experimentally manipulable animal model useful in studying animal mitochondrial DNA transmission genetics. The physical integrity of this mitochondrial genome appears to be in constant flux with respect to sequence amplification and deletion, and therefore provides a unique spectrum of related but distinguishable mitochondrial DNA molecules.Of particular interest are the deleted mitochondrial DNA forms, which will provide a useful genetic resource to investigate the generation and inheritance behavior of aberrant mitochondrial genomes that are the causitive agents of certain neuromuscular diseases in humans. The pilot experiments described in this application are designed to study the scope and tissue distribution of these novel mitochondrial DNA forms within individual nematodes and throughout nematode populations.